With regard to a device for filling a medicinal agent into a container, there has been conventionally proposed a method and a device for blending, in which various drugs are stored in three or more lines, and one vial size is allocated to each line, and at the time of filling of a prescription, the prescription is automatically allocated to one line and the processing is performed in accordance therewith from the viewpoint of the required vial size, thereby preparing for the case in which filling of the prescription is impossible, and then, all prescriptions of patients are collected and prepared as a single order (refer to, for example, Japanese Patent Laying-Open No. 6-127635 (PTD 1)).